Climatology of Ice clouds Derived from Polarization Lidar at AFARS, Fairbanks, Alaska

Arctic clouds play a crucial role in the global climate system through their radiative impacts and climate-feedback mechanisms. While it is generally recognized that changes in arctic cloud characteristics are due to large-scale atmospheric and oceanic circulation features, regional patterns and types of clouds are more sensitive to orography and weather phenomenon, which are poorly understood because of sparse measurements and are not well represented in climate models. A cloud research station (Arctic Facility for Atmospheric Remote Sensing, AFARS) established in central Alaska at the University of Alaska Fairbanks (64.85N-147.85W) supports a cloud polarization lidar (0.694μm) and W-band Doppler radar (3.2 mm) since 2004 with cloud and aerosol measurements during the local overpass times of the A-Train satellite constellation. Here we present a climatology of all ice clouds derived from our unique ~6 year lidar dataset and local radiosonde measurements. The clouds have been categorized by type according to the visual identification scheme of WMO by a single trained observer. The purpose of this study is to understand the conditions under which these types of cloud form with their macrophysical properties and associated weather patterns. In future these derived synoptic conditions and cloud properties will be used in algorithm development utilizing the present spaceborne active sensing datasets.